It is known that mixed metal oxide powders can be manufactured by hydrolysis of a metal alcoholate in the presence of a metal oxide or hydroxide, under certain conditions. For this purpose, U.S. Pat. No. A-4,636,378 (Hughes Aircraft Company) describes a process for the manufacture of a barium titanate powder exhibiting the tetragonal crystalline structure of perovskite, according to which a titanium alcoholate is introduced gradually into an aqueous solution of barium hydroxide, to form a gel of titanium oxide hydrate, the reaction mixture is then heated to above 100.degree. C. in an autoclave kept under pressure and then, after it has been cooled to ambient temperature, it is subjected successively to a moderate heating at atmospheric pressure and to a dialysis.
The disadvantage of this known process is that it is highly complex and that it requires a costly apparatus. Furthermore, the powder obtained exhibits a heterogeneous morphology, being made up of nonuniform particles and exhibiting a wide particle size distribution.
The invention overcomes this disadvantage of the known process by providing a new process which makes it possible to obtain, economically and easily, mixed metal oxide powders in the form of uniform spherical particles.